Rim curling apparatus



Dec. 22, 1970 Filed July 223, 1968 F. M. KULIG RIM CURLING APPARATUS 5 Sheets-$heet 1 I N VliN'l ()A.

FRANK M. KULIG ATTORNEY Dec. 22, 1970 1 F. M. KULIG 3,548,457

RIM CURLING APPARATUS Filed July 23, 1968 5 Sheets-Sheet 2 FIG 11' ATTORNEY:

Dec. 22, 1910 F. M. KULIG 3,548,457

RIM CURLING APPARATUS I I Filed July 23, 1968 5 Sheets-Sheet 5 ATTORNEY FRANK M. KULIG Dec. 22, 1970 F. M. KULIG 3,543,457

' Rm CURLING APPARATUS Filed July 23, 1968 5 Sheets-Sheet IAVIiA/IUR FRANK M. KULIG ATTORNEY Dec. 22, 1970 F.M.KU| |G 3,548,457

. RIM CURLING APPARATUS Filed July 23, 1968 r s Sheets-Sheet 5 [AVE/VIDA.

ATTQRNEY United States Patent 3,548,457 RIM CURLING APPARATUS Frank M. Kulig, Bloomfield, Courn, assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware Filed July 23, 1968, Ser. No. 746,868 Int. Cl. B29c 17/02; B29b 3/00 US. CI. 18-19 6 Claims ABSTRACT OF THE DISCLOSURE An improved cylindrical rim curling member comprising a plurality of short segments, each of which has a helically extending forming groove in its outer peripheral surface of uniform cross sectional configuration, but which differs in cross sectional configuration from that in substantially the remainder of the segments, with the segments being assembled together on end to form the member in a predetermined pattern wherein the changing configuration of the groove of the assembled segments conforms to the sequential manner in which the rim is deformed during the curling operation. In a preferred embodiment the segments are hollow and are assembled on a hollow shell.

This invention relates to containers and more particularly to apparatus for forming a smooth lip on a container.

When container blanks are severed from sheet material, the outer marginal edge of the container is left with a jagged edge which can cause cutting and irritation. The processes and apparatus for treating this edge to deform it inwardly out of the way so that the lips or fingers of a user will not contact it have recently become increasingly refined with emphasis being placed on the speed at which the edge is rolled inwardly to form a lip and the quality of the lips in terms of smoothness and dimensional consistency, the latter factor being important to insure flawless vendability of such containers from coin operated machines. Such advances in the art ore typified by US. Pat. Nos. 3,337,919 to Brown, 3,363,283 and 3,358,331 to Weber.

The Brown patent utilizes a single, helically extending, grooved forming roll in conjunction with a series of crowding rolls to curl a preheated jagged edge. The Weber patents utilize a series of helically grooved forming rolls spaced from each other to define an annular passage through which the container moves as its jagged edge is being heated and curled inwardly. The helical groove of each forming member in the latter system has a changing cross sectional configuration which serves to progressively gradually roll the projecting edge of the container in- Wardly as it passes through the annular passage. Though this latter system represents a valuable improvement, a problem involved in using this concept is that of providing the smoothly varying, helically extending grooved cross section in the surface of the cylindrical member, whether such a member is utilized in conjunction with crowding rolls or with a series of other similarly constructed members. Forming such a varying cross sectional con-figuration in the shape of a helix is just about a machining impossibility with conventional machining equipment, since the profile of the cutting tool for making the groove is fixed and ordinarily cannot be changed while continuously forming the helix.

Now a cylindrical roll structure having a changing helical groove cross section in its Outer periphery has been developed for use in lip forming or rim curling equipment which is simple and economical to construct.

Accordingly, it is an object of the present invention to provide an improved container rim curling apparatus.

It is another object of this invention to provide an im- Patented Dec. 22, 1970 proved forming roll structure for use in a container rim curling apparatus.

It is an additional object of this invention to provide an lmproved forming roll structure for use in a container I'll'l'l curlmg apparatus of the type wherein the rim of a container is heated as it is curled.

It is yet another object of this invention to provide an improved forming roll structure for use in a container rim curling apparatus of the type wherein the rim is heated before it is curled and/or cooled during or after curling.

It is a further object of this invention to provide a novel method of constructing a hollow cylindrical mem her having a helical groove of varying cross section in its outer peripheral surface.

It is a still further object of this invention to provide a hollow cylindrical member having a helical groove of varying cross sectional configuration in its outer peripheral surface which can be fabricated by conventional machine tool equipment.

It is yet a further object of this invention to provide an improved method and apparatus for overcoming the prior art difliculty discussed above.

These and other objects will in part be obvious and will in part appear hereinafter.

These and other objects are accomplished by providing an apparatus for curling a deformable projecting rim at one end of a container comprising forming means arranged on the circumference of a circle and including at least one rotatable forming member comprising a plurality of cylindrical segments, each having a helically extending groove in its outer peripheral surface which is different in cross sectional configuration from that of the grooves in substantially the remainder of the segments, at least part of the total length of the groove of the combined segments comprising a rim curling portion; means for holding the cylindrical segments together on end such that the groove of each segment interconnects with the groove of the next segment to form the forming member; the forming means arranged on the circle defining an annular passage through which the container passes with the rim thereof progressively engaged in the grooves of the segments; means for heating the rim of the container to a deformable state and means for rotating the forming means.

In a preferred embodiment the forming member comprises hollow cylindrical segments and a hollow shell having an outside diameter slightly less than the inside diameter of the cylindrical segments to permit the shell to engagingly slide within the hollow cylindrical segments.

Further provided in a method for constructing the previously mentioned forming member which comprises cutting an elongated, hollow, cylindrical body along planes perpendicular to its axis to form a series of axially short, cylindrical segments; machining a helically extending groove of constant cross section in the outer surface of each segment which is different from the cross sectional configuration of the groove in substantially the remainder of the segments; and fastening the hollow segments together on end in stacked relationship according to a predetermined pattern to form the forming member wherein the changing configuration of the groove of the assembled segments conforms to the sequential manner in which the rim is deformed during the curling process.

In describing the invention, reference will be made to preferred embodiments illustrated in the accompanying drawings in which:

FIG. I is a fragmentary, side elevational view of apparatus embodying the principles of the invention;

FIG. II is a fragmentary, end elevational view of the apparatus of FIG. I;

FIG. III is a fragmentary, sectional view taken on the line III-III of FIG. I;

FIG. 1V is a schematic perspective view of a portion of the apparatus of FIG. I in disassembled form;

FIG. V is a centrally sectioned elevational view of the parts of FIG. III when in assembled form;

FIG. VI is a partially sectioned elevational view of a typical container configuration for use with the apparatus of FIGS. I-V prior to passage through said apparatus;

FIG. VII is a view similar to FIG. V showing. the container subsequent to passage through the apparatus of FIGS. I-V; and

FIG. VIII is a centrally sectioned, elevational view of an alternate form of the apparatus of FIGS. 1V and V showing. parts in disassembled form.

Apparatus embodying the principles of the invention may comprise a supporting frame generally designated 10, formed of vertical and horizontal frame members 12 and 14, respectively, which are welded or otherwise suitably secured to one another. Fixed to the uppermost frame member 14 is a pair of spaced apart supporting members 16 and 18 which may be maintained in parallel relation by stringers 20 and 22. In member 16 is a generally egg shaped opening 24 over which lies a mounting. plate 26 which is secured to member 16 by bolts 28 or the like. The member 26 has a cylindrical opening 30 therein, around which is mounted forming means which comprise in part, a plurality of substantially uniform arcuately spaced, smooth surfaced crowding roll members generally designated 32, which function in the forming operation to be described. Each roll member 32 is constructed in the same manner, as generally depicted in FIG. I and comprises an inner spindle (not shown) secured to member 26 by means of lock nut 34. Sleeve 38 having a polished external metal surface is rotatably journaled on the fixed spindle by conventional bearings (not shown). The diameter of each sleeve 38 and its location relative to opening 30 are such that each roll member projects radially inwardly beyond the confines of opening 30, as is best shown in FIG. II. The end of each sleeve 38 is reduced in diameter at 380.

Although roll members .32 are arranged on the arc of a circle having its center at the center of the opening 30, rolls 32 do not form a circle. Instead, a number of rolls are omitted so that taken together the rolls which are employed present a horseshoe appearance, as viewed in FIG. II, for a purpose presently to be explained.

Accommodated in opening 24 at the upper end of the horseshoe configuration presented by rolls 32 is a helically grooved rim curling or forming member 40 as an additional part of the forming means. Forming member 40 comprises (FIG. IV) a plurality of axially short, hollow, cylindrical segments 42 of generally differing axial lengths. Each segment 42 has a helically extending groove 44 (FIG. V) in its outer peripheral surface, which is of a constant cross sectional shape throughout its length, but which is different in cross sectional shape from the groove in each one of the other segments 42. Each member 40 further comprises a hollow cylindrical shell portion 46 having a side wall 48 and a pair of opposed spaced end walls 50 secured to side wall 42 at either end thereof so as to define a heat chamber 52 within each rotatable forming member 40. Shell 46 is secured to a spindle 54 which is journaled by bearings (not shown) in a tubular housing 56, which in turn is fastened by means of bolt 58 to mounting member 16. Segments 42 are of considerably greater diameter than roll sleeves 38. The axis of rotation of forming member 40 lies on a plane passing through the center of the circle in which the crowding rolls 32 are arranged.

Spindle S4 is provided with heating medium inlet and outlet passages which communicate with a rotatable coupling 60 which is rotatably mounted on spindle 54 and to which are connected heating medium inlet and outlet conduits 62 and 64, respectively, by means of which a heat 4 transfer medium may be circulated from a source, through forming member 40 so as to maintain the external surface thereof at a predetermined temperature.

The outside diameter of side wall 48 of each shell 46 is incrementally less than the inside diameter of each cylindrical segment 42 to permit shell portion 46 to be assembled with minimum clearance between the hollow cylindrical segments 42 in a manner generally depicted in FIG. VI. In so doing, the inner surfaces of each segment 42 are for heat transfer purposes in contact with the exterior surface of side wall 48 of shell portion 46, to permit a conductive type of heat transfer to occur between the shell and the segments to raise the temperature of the rim curling surfaces of the helical grooves 44 of the segments 42.

Means are provided for rotating the forming means which includes forming member 40 and crowding roll members 32, and comprises an electric motor 66 having its armature shaft 68 connected by a belt 70 or the like to a pulley 72 which is fixed on shaft 74 which in turn is journaled in bearing 76 supported on the main frame 10. Also fixed on shaft 74 is a driving pulley 78 around which is trained an enless drive belt 80 having transversely extending longitudinally spaced apart traction providing grooves which pass around the periphery of segments 42 and which are in tangential engagement with a plurality of the crowding rolls 32. Suitable tension is maintained on the driving belt 80 by a pair of wheels 82 and 84 journaled on mounting member 16 between the driving pulley 86 and the crowing rolls 32.

Interposed between members 16 and 18 is an electric heating unit 88 which comprises two semicylindrical housing sections 90 provided with arms 92 which pivotally mount the half sections on stringers 20 Each half section 90 is connected one to another to form a sleeve of such size as to accommodate a stack of nestable containers C having closed ends and generally radially extending flanges F at their open ends. A container C having a flange F prior to the rolling operation is more clearly typically depicted in FIG. VI. Located within the heating unit 88 is a plurality of conventional electrical resistance heating elements 94 which may be connected to a source (not shown) of electric energy. The longitudinal axis of the heating unit 88 coincides with the axis of opening 30. Preferably, guide rods 96 extend through the heating unit so as to properly position and support the containers in the latter.

Means is provided for forwarding or driving the stack of nested containers C through the heating unit 88 and comprises a plurality of forwarding rolls 98 formed of soft rubber or the like and journaled on spindles 100 which are inclined to the longitudinal axis of the heating unit. Each spindle 100 is journaled on a bracket 102 which is adjustably mounted in a support 104 that is secured to the mounting member 18. The supports 104 are spaced about an opening formed in plate 18, but the rolls 98 project inwardly beyond the edge of the opening so as to be capable of gripping the containers. The arrangement is such that the inclination of the axis of rotation of the rollers may be adjusted so as to control the plane at which containers are fed to the heating unit. Each spindle 100 has fixed thereto a driven pulley 106 around which is trained a drive belt 108 which is driven from a pulley 110 fast on the shaft 74.

Returning now in more detail to the construction of rim curling or forming member 40, and as best depicted in FIGS. IV and VI, means 112 are provided for holding the cylindrical segments 42 together on end in contact with the exterior surface of side wall 48 of shell 46. These means comprise a keyway having an elongated rectangular slot 114, one half of which is formed in side wall 48 of the shell and the other half of which is cut in the inner surface of each cylindrical segment 42. Key 116, having dimensions similar to those of keyway 114, is adapted to be fitted within keyway 114 after segments 42 are stacked in place on shell 46 so as to prevent rotation.

of segments 42 with respect to shell 46. Means 112 further comprises a shoulder 124 on one of the end walls 50 of the shell extending outwardly from the periphery of side wall 48 and terminating at or short of the minimum diameter of helical grooves 44 of cylindrical segments 42. Shoulder 124 serves to support the segments at one end of the shell when placed thereon. Further provided is a circular end plate 116 having a diameter generally equivalent to that of shoulder 124 which is fastened by means of bolts 120 in threaded holes 122 extending through clearance holes 118 to the other of the shell end walls after the segments are placed on the shell, in order to secure them axially between shoulder 124 and end plate 116.

In FIG. VIII is shown an alternate embodiment of the structure of forming member 40 of the present invention in which shell 46 has been eliminated. In this embodiment the cylindrical segments 126 are fastened together by means of three or more tie rods 128 having threaded ends for accepting fasteners 130 on each end. The tie rods are placed in holes 132 formed in each segment and equally spaced at three points around the outer margin of each. Flange 134 and end cap 136 each of which have diameters substantially equivalent to the minimum diameter of the grooves in the cylindrical segments replace the end walls of the shell of the previous embodiment. Cylindrical slots 138 and 140, oppositely aligned when the segments are assembled, are provided for a suitable gasket such as a resilient O-ring, to prevent leakage of the heat transfer medium from between the segments. Projections 142 and depressions 144 are provided in succesively positioned segments as an aid in assembling the complete member to prevent radial slippage between the segments. Drilled holes 146 are provided in the outer margin of each segment, which are reamed at 148 to accept a press fit dowel pin 150 with the other end portion 152 of each hole 148 reamed for a slip fit acceptance of the corresponding end portion of the dowel pin. These dowel pins function to prevent any peripheral slippage of the segments with respect to each other after they are assembled, since the leading edge of the groove of one piece must line up exactly with the trailing edge of the groove in the next adjacent piece in order to remove the possibility of a forming groove discontinuity.

After the segments are assembled together, some blending, i.e. removing of metal in the area of the abutting trailing and leading edges of the grooves of successive segments is necessary to provide a smooth transition between the two parts.

Obviously, similar results with respect to fastening of the segments could be obtained by dividing up the tie rods, i.e. by joining the successive segments, one to the other, with separate screws. However this requires considerably more effort to disassemble the entire forming member should it be necessary to service or change an interiorly positioned segment of the member. Fastening by bolting, as above described, could be replaced by welding, however this results in a much more inflexible member, since if it is desired to slightly change the contour of the lip or rim being formed, it would most likely be necessary to discard the entire member, whereas with bolted connections only a portion of the segments need be remachined.

In operation of the apparatus, a stack of nested containers C are presented to the feeding wheels 98 so as to enter the opening in frame 18 with their base end foremost. The containers may be delivered to the feeding wheels by means of a U-shaped trough 125 or other suitable conveyor, which supports the containers in such position that the flanges F will be engaged by rolls 98 and with suflicient friction to feed the stack of containers into and through the heating unit 88, where the containers are supported by guide rods 96. As the containers are moved through the heating unit, the flanges F will be preheated and softened so as to be readily deformable. The flanges F may have axial return portions as shown in FIG. VI or in the alternative may terminate in radial edges. From the heating unit 88, the containers are driven forwardly by forwarding wheels 98 to the space between the forming means comprising crowding rolls 32 and forming member 40. The positions of the roll portions 38a taken together with the position of the surface of the leading portion of the forming member 40 are such that the rolls 38 position the flange F of each container initially in a manner to assure its proper entry into the leading portion of the forming groove 44, without undue pressure from crowding rolls 38.

Upon introduction of the flange F of a container C in the curling groove 44 of forming member 40, the crowding rolls 32 which are driven by the belt will tend to impart rotation in one direction to the container. Member 40 also will be rotated by belt 80 but in a direction opposite to the direction of rotation of the container. As belt 80 rotates, it assures rotation of the forming member 40 and the container relative to one another in opposite directions so as to advance the container axially of the forming member and simultaneously curl the flange F to form a head or rolled edge for the open end of the container, as depicted in FIG. VII. The container stack rotates as a unitary body during its passage from the advancing rolls 98 through the machine.

As each container C passes through the forming means, its rim is successively engaged in grooves 44 of segments 42 of forming member 40. A suitable heating medium is passed through heating chamber 52 through inlet and outlet conduits 62 and 64 and hollow spindle 54 in order to maintain flanges F of containers C at elevated temperature as they are being deformed in the helical groove of forming member 40. The uniform cross section of the helical groove of each segment, which is diiferent from that of subsequent segments in the stack, basically permits dividing the total extent of movement of each container flange during the rim curling into a series of steps wherein the flange is progressively and incrementally rolled inwardly as it contacts the groove surface of the successive segments into the final configuration depicted in FIG. VII. The partially rolled rim is held at each particular intermediate curling position corresponding to the helical groove cross sectional configuration of a particular segment for a finite period while the container continues to rotate, because of the uniform cross section of the groove in that segment, before proceeding smoothly to the next subsequent position, thereby insuring complete deformation in a stepwise manner.

Containers leaving the forming means pass through opening 30 in plate 26 and are received in a trough 127 similar to trough 125, or in any other suitable conveyor.

The above description and particularly the drawings are set forth for purposes of illustration only and are not to be taken in a limited sense.

The composite forming member structure of the present invention is applicable equally as Well to the type of rolling apparatus utilizing a single member as above described, or in the type utilizing a plurality of such members equally radially disposed from a common central axis defining a passageway through which the containers pass either individually or in nested stacks.

Heating of the cylindrical forming member may be achieved, for example, by means of high frequency induction type of heaters positioned adjacent an exterior portion of the rotating forming member. In such cases the segments of the present invention could therefore be solid, or bored only to a small extent of their radii.

Suitable solid spacer pieces may be interposed between the-hollow segments so as to establish separate chambers within a given cylindrical forming member in order, for example, to permit cooling portions of the groove surfaces to set the hot plastic after the rim has been curled, and prior to ejection from the forming means. The segmented roll structure is likewise applicable to the formation of such a cooling chamber, either separately or in combination with an integral heating chamber in the member.

The number of segments making up a cylindrical forming member may vary, depending on the type of edge presented to the forming apparatus for curling. It has generally been found that from 3 to 11 segments and preferably 3 to 9 segments are adequate to handle most container designs.

The present invention eliminates the machining problem of providing a helical groove of varying width, shape and depth by utilizing a number of segments having helical grooves therein of uniform configuration, but wherein the groove of each segment differs from that of substantially the remaining segments.

Various modifications and alterations will be readily suggested to persons skilled in the art. It is intended, therefore, that the foregoing be considered as exemplary only, and that the scope of the invention be ascertained from the following claims.

What is claimed is:

1. An apparatus for curling a deformable projecting rim at one end of a container comprising:

forming means arranged on the circumference of a circle and including at least one rotatable forming member comprising a plurality of cylindrical segments, each of said segments having a helically extending groove in its outer peripheral surface of uniform cross sectional configuration which is different from the cross sectional configuration of the grooves in substantially the remainder of the segments, at least part of the total length of the groove of the combined segments comprising a rim curling portion and means for holding the cylindrical segments together on end such that the groove of each segment interconnects with the groove of the next adjacent segment, to form the forming member; the forming means as arranged on said circle defining an annular passage through which the container passes with the rim thereof progressively engaged in the grooves of the segments;

means for heating the rim of the container to a deformable state; and

means for rotating the forming means.

2. In an apparatus for curling deformable projecting rim at one end of a container comprising forming means arranged on the cicumference of a circle and including a rotatable forming member having a helically extending groove therein to accommodate the rim of the container, at least part of said forming member comprising a rim forming portion, means for heating the rim of the container to a deformable state and means for rotating the forming means, the improvement which comprises a plurality of axially short, cylindrical segments, each having a helically extending groove in its outer surface which is uniform in cross sectional configuration yet is different in cross sectional configuration from that of the helically extending groove in the remaining cylindrical segments, said cylindrical segments being arranged in stacked formation with their end surfaces abutting against each other and the leading and trailing edges of the grooves in successively stacked segments blending smoothly together and means to hold said stacked segments together to define said rim forming portion of the rotatable forming member.

3. The apparatus of claim 2 wherein said means to hold said segments together comprises a plurality of tie rods extending through holes in the peripheral margin of each of said segments and threaded fasteners for each end of said tie rods arranged for advancement toward each other when threaded inwardly on each tie rod.

4. The apparatus of claim 2 wherein the axial length of each segment is different for that of the remaining segments.

5. An apparatus for curling a deformable projecting rim at one end of a container comprising:

forming means arranged on the circumference of a circle and including at least one rotatable forming member comprising a plurality of hollow, axially short cylindrical segments, each of said segments having a helically extending groove in its outer peripheral surface of constant cross section which differs from that of the grooves of the remainder of the segments, a hollow cylindrical shell having a pair of spaced end walls, the outside diameter of said shell being slightly less than the inside diameter of each of said cylindrical segments to allow said shell to slide within said hollow cylindrical segments, the hollow interior of said shell defining a heating chamber and means associated with said shell and said segments to hold said segments together in stacked abutting relation in contact with the exterior surface of said cylindrical shell, thereby defining said forming member; means for increasing the temperature of the heating chamber of said at least one forming member; and means for rotating the forming means.

6. The apparatus of claim 5 wherein the means for holding said segments together comprises a keyway in the outer surface of said shell and on the inner surface of each of said segments, a shoulder on one of the end walls of the shell which extends outwardly from the periphery thereof, terminating short of the minimum diameter of the grooves of said cylindrical segments to support said segments at one end of the shell when placed thereon, a key for insertion into said keyway to prevent said segments from rotating when placed on said shell and a circular end plate having a diameter generally equivalent to said shoulder for bolting to the other of said shell end walls after said segments are placed on the shell.

References Cited UNITED STATES PATENTS 2,970,343 2/1961 Johnson et al 1845(M) 3,096,546 7/1963 Edwards 18l9(BC)X 3,337,919 8/1967 Brown 18-19(BC) 3,339,005 8/1967 Brown et al 18l9(BC) 3,355,536 11/1967 Midgley et a1. 1819(BC)X 3,358,331 12/1967 Weber 18l9(BC) 3,363,283 1/1968 Weber 18l9(BC) J. SPENCER OVERHOLSER, Primary Examiner R. L. SPICER, JR., Assistant Examiner 

